The present invention relates to an apparatus for processing wafers in a vacuum chamber. More particularly, the invention relates to an apparatus for removal of heat from a vacuum chamber.
Connecting a power source, such as a radio frequency (xe2x80x9cRFxe2x80x9d) power source, to a device, such as an RF antenna coil, through the wall of a vacuum chamber typically involves providing an insulated passage through one or more deposition shields. Application of RF energy to the coil tends to generate heat within the chamber. This heat is dissipated through radiation and conduction to heat sinks typically the shield, target, etc. within the chamber. Deposition shields are typically constructed of stainless steel for strength and tend to be negatively charged or grounded during wafer processing. Furthermore, the shield accumulates heat during wafer processing and chamber cooling declines unless the additional heat is removed from the shield. There is a need, therefore, for a deposition shield which avoids build up of additional heat within the vacuum chamber.
The present invention provides an aluminum deposition shield which substantially improves transfer of radiated heat from within the vacuum chamber, to external chamber components in comparison to a conventional stainless steel deposition shield. The aluminum deposition shield remains cooler during wafer processing and assists in cooling the chamber components.